Pulverizing apparatus for coal, etc.



A ril 3, 1934. F. a. PARKER 1,953,125

PUL'VERIZING APPARATUS FOR GOAL, ETC

Filed Sept. 21, 1929 2 Sheets-Sheet l A ril 3, 1934. F. s. PARKER PULVERIZING APPARATUS FOR COAL, ET

Filed Sept. 21, 1929 2 Sheets-Sheet 2 Patented Apr. 3, 1934 1,953,125 PULVERIZIN G APPARATUS FOR COAL, ETC.

Frank G. Parker, Jersey City, N. J. Application September 21, 1929, Serial No. 394,212

Claims.

This invention relates to pulverizing apparatus, having reference more particularly to apparatus for pulverizing fuel and feeding it to the fire-box of a furnace.

An object of my invention is to provide an apparatusof simple and efficient construction and operation whereby coal and other bulk material are rapidly and eiiiciently pulverized by attrition.

Another object is to provide such a construction whereby tramp iron and other hard foreign objects are trapped before their passage to the action of the attrition elements.

Another object is to provide such a construction whereby the pulverized fuelis intimately mixed with air before its passage to the fire-box of a furnace.

Another object is to provide such a construction whereby the attrition elements can be relatively adjusted to compensate for wear, etc.

With these and other objects in view my invention embodies novel features of construction and combinations of parts, which will be hereinafter described; the scope of the invention then being defined in the appended claims.

In the drawings- Figure l is a sectional elevation of an apparatusembodying my invention, showing the same as associated with the fire-box of a locomotive.

Figs. 2 and 3 are transverse'sections, as on the lines 2-2 and 3--3, respectively, of Fig. 1.

Fig. 4 is an end view of a discharge conduit for the grinder casing, showing an adjustable endthrust bearing for the drive shaft.

Fig. 5 is an end elevation of an air-inlet section opening into the fire-box.

Fig. 6 is an elevation of the rotary grinder elements and a portion of the shaft therefor.

Fig. '7 is a sectional detail of the adjustable end-thrust bearing for the grinder shaft.

Referring to the drawings, 10 designatesa portion of a furnace having an inlet 11 for pulverized fuel, which furnace may comprise the fire-box of a locomotive whereof the cab 12 is supported above the inlet 11.

Depending from the floor beams 13 of the cab, or other suitable supporting structure, is a pulverizing mill whereof the casing includesa forward cylindricalmain head 14 which is bolted to the floor beams 13 in spaced relation to the furnace inlet. This head is provided with a nozzle formed with a conical or tapering chamber 15, the reduced end of which opens into a cylindrical mixing chamber in a conduit 16 coaxial therewith, which conduit is provided with a series of inclined vanes 1'7 against which the pulverized fuel and primary air impinge on their passage through the conduit, as will presently appear. This conduit is bolted to the head 14 and leads directly to a burner 18 which is seated in the inlet. This burner comprises a cylindric section the periphery of which is formed with an annular peripheral opening 19 leading from the outer air to the inlet of the furnace. The annular opening is provided with a series of spaced-apart vanes 23 which are inclined reversely of the vanes 17 and are adapted to swirl the secondary air as it passes through the opening 19 to the inlet.

The casing head 14 is formed adjacent its forward end with an annular air chamber 21 which tapers to a narrow annular exitopening 22 surrounding the nozzle at the forward portion of the chamber 15, whereby air under pressure introduced to said annular chamber 21, as hereinafter described, is discharged in a path leading to the mixing chamber in the conduit.

The rear of the casing head 14 has bolted thereto an extension 23 having in its interior two spaced apart conical walls 24, 25 provided with members 26, 27 having attrition surfaces with which co-act conical grinder heads 28, 29, respectively, fast on a horizontal driven shaft 30. One end of this shaftextends into the conduit 16 and is journaled in a central bearing therein. In the present instance this bearing comprises a hub 31 integral with the vanes 1'7 of the conduit 16, which hub is internally threaded and receives a threaded plug 32 that abuts a ball thrust bearing 33 at the end of the shaft. Hence the plug can be adjusted longitudinally of the hub to effect corresponding adjustment of the shaft and the grinder elements, thereby compensating for the wear of the latter and positioning them in eflicient working relation to the respective attrition surfaces of the members 26,27 on the walls 24, 25 of the casing. As a simple and efficient means to adjust the screw plug 32 it is provided at its outer end with a worm wheel 34 with which engages a worm 35 on a transverse key shaft 36 having its bearings in the wall of the conduit 16. (See Figs. 1 and l).

Bolted to the receiving end of the casing .extension 23 is .an elbow at the foot .of a vertical conduit .360 which depends from the floor .beams 13 and communicates with an opening 37 leading to the interior of the cab 12. Fuel to be pulverized may be delivered to the opening in any suitable manner, as for instance, by a screw conveyer 38. The fuel thus delivered is fed by way of the conduit 360 to the primary grinder element 28 at the receiving end of the casing, and as this element is rotating at high speed such fuel is reduced by attrition against the opposing surface of the member 26 and is carried forwardly 5 through the casing by the action of the air ourrent which is induced by the air under pressure flowing through the annular opening 22 of the casing head 14. The particles of fuel are carried by the air current to the second grinder element, where they are further reduced and then drawn into the conduit 16 whence they pass through the cylindric burner in the furnace inlet. As the powdered material flows between the vanes 17 of the conduit 16 such material is rapidly swirled by its impact with the opposing inclined surfaces of the vanes 17, thus effecting an intimate mixture of the coal and air preparatory to and during their entry into the furnace inlet. At the same time the secondary air entering the inlet through the annular opening 19 of the burner 18 is swirled in a direction reversely of the swirling mixture of coal and air, thus ensuring a still more intimate mixture of the coal air and consequently promoting the GfijClSllCY of the fuel.

As illustrated in Fig. 1 the outer face of the primary grinder element 28 is formed witha circular recess 39 having a conical or inclined wall 40 merging with an annular pocket or trap ll. This recess receives the material at the foot of the feed conduit, and hence in the event of the presence of hard foreign objects, as tramp iron, in thecoal, such objects will be thrown by centrifugal force into the pocket 41 and be trapped thereby. In this way the passage of tramp iron and the like between the attrition surfaces will be prevented. The bottom of the feed conduit 360 is provided with a suitable discharge opening 42 having a hinged or movable door 3, which door may be opened from time to time to permit the ready removal of the trapped accumulations.

This trap construction is an important feature of my invention.

In the present instance the shaft 30 has a bearing in one side of the feed conduit 366, as at 44, and also in a bracket 45 depending from the floor beams 13. Fast on this shaft is a turbine 46 of any usual or approved construction by means of which the shaft is rapidly rotated. The shaft has also mounted thereon the blades of a fan 47, the discharge of which fan is connected by means of pipes 48 with the annular air chamber 21 of the casing head 14, whereby air under pressure is delivered to said annular chamber for the purpose hereinbefore mentioned.

While I have herein described my invention as applied to a locomotive furnace, it is to be understood that it may be applied to other furnace constructions, and may also, if desired, be utilized as an attrition mill irrespective of the furnace. The invention is therefore not limited to the particular construction herein disclosed, as the structure may be modified within the principle of the invention and the scope of the appended claims.

I claim 1. In a pulverizing apparatus, the combination of a casing having an attrition surface, a grinder element mounted to rotate on a horizontal axis within said casing and to co-act with said surface, means for rotating said element, means for producing a current of air across the periphery of said element, and means for feeding material to be pulverized to the receiving face of said element, said face having therein a recess merging with an annular pocket constituting a trap for hard foreign material.

2. In a pulverizing apparatus, the combination of a casing having an attrition surface, a grinder element mounted to rotate on a horizontal axis within said casing and to co-act with said surface, means for rotating said element, means for producing a current of air across the periphery of said element, a conduit for feeding material to be pulverized to the receiving face of said element, said conduit having an opening and door whereby access can be had to said face, and said face having therein a recess merging with an annular pocket constituting a trap for hard foreign material.

3. A pulverizing apparatus, comprising a casing having a chamber with an attrition surface th rein, a grinder element coacting with the attrition surface in said chamber, means to rotate the grinder element, an inlet opening at one end of the chamber for the material to be pulverized, a converging nozzle extending from the other end of the chamber, a conduit beyond the nozzle, there being an annular chamber having converging walls surrounding the nozzle, there being an annular opening from said chamber at the edges of the converging walls between the nozzle and the conduit, and means independent of the casing and grinder for supplying air under pressure directly to the annular chamber to draw the pulverized material from the chamber in the casing and force it through the conduit.

4. In a pulverizing apparatus, the combination of a casing having an attrition surface, a hollow head and a conduit at the delivery end of the casing, said head having a nozzle and an annular air chamber surrounding the nozzle opening into the conduit, a grinder element mounted to rotate on a horizontal axis within said casing and having an attrition surface to co-act with said attrition surfaceon the casing, the receiving'face of said grinder having therein a recess merging with an annular pocket constituting a trap for hard foreign material, means for rotating said grinder element, means for feeding material to be pulverized to the receiving face of said element, and means for supplying air under pressure to said annular chamber.

5. In a pulverizing apparatus, the combination of a casing having a conical attrition surface, a hollow head at the delivery end of thecasing having an annular air chamber and also having an annular nozzle leading from said chamber to the interior of the head, a shaft extending axially of said casing, an adjustable bearing member for one end of the shaft, means for adjusting said member, a conical grinder element on said shaft co-acting with said attrition surface, means for rotating said shaft, means for feeding material to be pulverized to the said element, and means for supplying air under pressure to said annular chamber.

FRANK G. PARKER. 

